TWI540221B - Systems and methods for thin-film deposition of metal oxides using excited nitrogen-oxygen species - Google Patents

Description

System and method for depositing metal oxide thin films using excited nitrogen-oxygen species Cross-reference to related applications

This application is related to and claims the provisional application No. 61/234,017 and 2010, filed on August 14, 2009, entitled "SYSTEMS AND METHODS FOR THIN-FILM DEPOSITION OF METAL OXIDES USING EXCITED NITROGEN-OXYGEN SPECIES" The priority of Provisional Patent Application No. 61/332,600, entitled "SYSTEMS AND METHODS FOR THIN-FILM DEPOSITION OF METAL OXIDES USING EXCITED NITROGEN-OXYGEN SPECIES", filed on May 7, the disclosure of which is incorporated by reference. Incorporated herein.

Invention narrative

This invention relates to thin film deposition, and more particularly to systems and methods for depositing metal oxides using precursors by atomic layer deposition using ozone and excited nitrogen-oxygen species.

Cerium oxide (SiO ₂ ) has been used in semiconductor substrates for components such as transistor gate dielectrics and capacitor dielectrics for many years. However, as the size of the circuit member is reduced, the electrical performance characteristics of SiO ₂ cause undesirable effects such as an increase in leakage current. When using SiO ₂ or the like, such as a dielectric older generation manufactured newer integrated circuit geometries, the challenge is to control the leakage current to maintain a high speed low power performance.

Newer methods, especially those that use manufacturing geometries of less than 65 nm, have begun to include high dielectric constant ("high-k") insulators in semiconductor fabrication. Especially for process geometries of 45 nm and smaller, some wafer manufacturers now rely on high-k dielectrics. For achieving smaller device geometries while controlling leakage and other electrical performance criteria, it is important to replace the SiO ₂ gate dielectric with a high-k dielectric.

While the use of high-k dielectrics allows for a smaller scale of integrated circuit components such as transistor gate dielectrics, there are challenges in their manufacture. Although certain metal oxides and rare earth oxides such as zirconia, titania, cerium oxide, cerium oxide, aluminum oxide, cerium oxide, and cerium oxide are known to provide desirable characteristics when deposited as a thin film, in a method of fabrication There are still challenges, such as incompatibility between process chemistry, extended deposition cycle times, and lesser required deposition uniformity.

There are various methods and related devices for providing a film on a substrate such as a semiconductor. Some methods form thin films on substrates by utilizing surface reactions on semiconductors, such as vacuum evaporation deposition, molecular beam epitaxy, chemical vapor deposition (CVD), different variants (including low pressure CVD, organometallic CVD, and plasma). Enhanced CVD) and atomic layer epitaxy (ALE). ALE is also known as atomic layer deposition (ALD).

ALD is a method of depositing a thin film on a substrate surface by introducing various precursor species in sequence. Conventional ALD devices can include a reaction chamber (comprising a reactor and a substrate holder), a gas flow system (including a gas inlet for providing precursors and reactants to the surface of the substrate, and an exhaust system for removing the gas used). The growth mechanism relies on adsorbing the precursor on the active site of the substrate, and preferably maintains the condition such that only a single layer is formed on the substrate, thereby self-terminating the process. After exposing the substrate to the first precursor, typically a rinse phase or other removal process (eg, evacuation or "extraction"), wherein any excess first precursor and any reaction byproducts are removed from the reaction chamber. The second reactant or precursor is then introduced into the reaction chamber where the second reactant or precursor reacts with the first precursor and the reaction produces the desired film on the substrate. The reaction is terminated when all of the available first precursor species adsorbed on the substrate have reacted with the second precursor. A second rinse or other removal stage is then performed to remove any remaining second precursors and possible reaction by-products from the reaction chamber. This cycle can be repeated to grow the film to the desired thickness.

A known advantage of ALD over other deposition methods is that as long as the temperature is within the ALD window (which is above the condensation temperature of the reactants and below the thermal decomposition temperature of the reactants) and provides sufficient reactants in each pulse Saturating the surface is self-saturating and uniform. Therefore, in order to obtain uniform deposition, it is not necessary to have a uniform temperature and gas supply.

ALD is further described in the Finnish Patent Publication Nos. 52,359 and 57,975, and U.S. Patent Nos. 4,058,430 and 4,389,973. The apparatus for carrying out such methods is disclosed in U.S. Patent Nos. 5,855,680, 6,511,539 and 6,820,570, Finnish Patent No. 100,409, 1989, Material Science Report 4 (7), page 261, and Tyhjiotekniikka (for vacuum technology). Finnish Announcement), ISBN 951-794-422-5, pp. 253-page 261.

Different film materials have been deposited using ALD. Known materials for ALD include binary oxides such as Al ₂ O ₃ , HfO ₂ , ZrO ₂ , La ₂ O ₃ and Ta ₂ O ₅ . Various ternary oxides are also well known materials for ALD and include HfZrO, HfAlO, and HfLaO. As previously stated, the selection of suitable materials for high-k dielectric applications requires consideration of the effects of the deposited materials on the particular substrate and circuit environment, as well as the need to consider process chemistry. In the ALD condition of HfLaO, the Hf-precursor is known as HfCl ₄ and the La-precursor is known as La(THD) ₃ . Since the hygroscopic properties of the La ₂ O _3, in the prior art methods typically using ozone (O ₃₎ instead of H ₂ O as the oxidizing agent, but regret, HfCl ₄ / O ₃ Method and La (THD) / O ₃ Method Both are highly sensitive to even small changes in the presence of ozone. In some instances, the use of ozone also results in less than the desired uniformity of the deposited oxide film. In addition, when a single oxidant (such as ozone) is required to be used in a manner that achieves effective and consistent deposition results regardless of the type of metal precursor used in the deposition process, controlling two different oxidative chemistries complicates the deposition process .

A plasma discharge can be used to excite the gas to produce an activating gas containing ions, free radicals, atoms, and molecules. Activated gases are used in many industrial and scientific applications, including processing solid materials such as semiconductor wafers, powders, and other gases. The plasma parameters and the conditions under which the plasma is exposed to the material being processed vary widely depending on the application.

Plasma can be produced in a variety of ways, including current discharge, radio frequency (RF) discharge, and microwave discharge. Current discharge is achieved by applying a potential between two electrodes in a gas. RF discharge is achieved by electrostatically or inductively coupling energy from a power source into the plasma. Parallel plates are typically used to electrostatically couple energy into the plasma. Induction coils are commonly used to sense current into the plasma. Microwave discharge is achieved by directly coupling microwave energy into a discharge chamber containing a gas via a microwave pass window. Microwave discharge is advantageous because it can be used to support a wide range of discharge conditions, including highly ionized electron cyclotron resonance (ECR) plasma.

The ALD system has used a plasma based approach to generate oxidant gases such as ozone. In one common configuration, the dielectric barrier discharge (the DBD) from the ozone generator feed gas is supplied as the oxygen supply to the corona discharge (O ₂₎ to generate ozone (O _3). Referring to Figure 5, a simplified DBD ozone generator unit 500 is illustrated. Typically, dry feed gas oxygen 530 is passed through a gap 505 formed between electrode 510A and electrode 510B, which is alternately energized by a high voltage source such as an alternating current (AC) voltage source 560. The voltage generated by the source 560 can be several thousand volts depending on the configuration of the generator. Alternatively, one of the electrodes can be at ground potential and the other electrode can be energized to a high voltage. The dielectric material 520A and the dielectric material 520B are interposed between the energized electrode 510A, the electrode 510B, and the feed gas 530. When a low-frequency or high-frequency high voltage is applied to the electrode 510A and the electrode 510B, the ozone 550 is generated in the feed gas by the micro-discharge occurring in the gap 505 and distributed across the dielectric 520A and the dielectric 520B. The geometry of the gap and the quality of the dielectric material vary with the ozone generator manufacturer. Notably, the DBD device can be fabricated in a number of configurations (typically a flat configuration) using a parallel plate that is separated by a dielectric or cylindrical, using a coaxial plate with a dielectric tube interposed therebetween. In a shared coaxial configuration, the dielectric is shaped to be the same shape as a shared fluorescent tube. The dielectric is filled with a rare gas or a mixture of rare gas halides under atmospheric pressure, and a glass wall is used as a dielectric barrier. Common dielectric materials include glass, quartz, ceramics, and polymers. The gap distance between the electrodes varies significantly from 0.1 mm to several centimeters depending on the application. The composition of the feed gas is also an important factor in the operation of the ozone generator.

High-efficiency ozone generators using the DBD principle require nitrogen fed into the gas for optimum performance and consistent ozone generation. The formation of ozone involves a reaction between an oxygen atom, an oxygen molecule, and a collision partner such as O ₂ , N ₂ or possibly other molecules. If the collision partner is nitrogen, the nitrogen molecules are able to transfer their excitation energy (after impact) to the oxygen molecules, resulting in dissociation. Some of the excited nitrogen radicals formed may also dissociate or react with the nitrogen oxides to release oxygen atoms. Many different forms of nitrogen-oxygen compounds -NO, NO ₂ , N ₂ O and N ₂ O ₅ can be produced in the process, and these nitrogen-oxygen compounds have been measured in an output DBD-type ozone generator. . Some manufacturers are already working to reduce or eliminate the presence of certain NO species from their ozone generator output ozone streams. For example, in some cases, corrosive corrosion of NO compounds to gas lines and welds may occur in the ozone stream. . In conventional ozone generators, there is a lack of control over the presence and type of NO compounds in the output stream of the ozone generator, and it is desirable to be able to monitor and/or actively control the formation and production of such compounds.

Therefore, there is a need for a method of depositing a dielectric film having enhanced deposition uniformity on a substrate with reduced process time. There is also a need for a system to monitor and/or control nitrogen-oxygen compounds produced in an oxidant generator such as an ozone generator.

The present invention comprises for depositing on a substrate with enhanced deposition efficiency and uniformity such as hafnium oxide (HfO ₂ ), zirconium oxide (ZrO ₂ ), lanthanum oxide (La ₂ O ₃ ) and yttrium oxide (Ta ₂ O ₅ ). A method and system for a metal oxide film. The specific performance of the present invention utilizes an ALD system that combines various precursors, as set forth below, combining molecules and exciting nitrogen-oxygen radicals/ion species (hereinafter referred to as "N _x O _y species", where "x" and "y" Any suitable integer may be constructed, and the N _x O _y species may comprise an excited species such as NO* and N ₂ O*, possibly in combination with an oxidizing agent such as ozone. Specific manifestations of the invention also include electronic components and systems comprising devices made by methods consistent with the present invention.

During an experiment conducted in an ALD deposition of a thin film metal oxide using a metal halide precursor/ozone oxidant chemistry, no observation was observed on the substrate when the substrate was exposed to an ozone oxidant that had been produced by the use of pure oxygen fed gas. Growth occurs. However, when gaseous nitrogen is added to the oxygen stream in the ozone generator (as is commonly practiced to increase ozone production efficiency), layer growth is observed during the ALD deposition process. For example, in various tests using ozone generated from pure oxygen, a uniform HfO ₂ layer or ZrO ₂ layer cannot be deposited at 300 ° C, but when ozone is generated by oxygen/nitrogen feed gas, uniform deposition can be performed. Floor. Different tests have also shown that the growth rate and uniformity depend on the amount of nitrogen used in the ozone generator relative to the amount of oxygen fed gas.

It was further determined by experiments that the concentration of the N ₂ feed gas used to generate ozone has an influence on the deposition process. 10 shows such a graph of the test, where N ₂ 0 ppm uniformly exhibit little growth, 40 ppm causes an increase in the growth of N _2, and N ₂ when adjusted to 400 ppm, significant growth occurs uniformly. Then, as illustrated in Figures 11-12, additional experiments were performed using closed loop control and with the NH ₂ flow in the 2.5 slm, 18 wt% ozone generator as the nitrogen concentration shown in the graph changed. The ozone injection stream entering the reaction chamber was 1200 sccm. Over 3 seconds HfCl ₄ precursor is pulsed into the chamber, followed by rinsing for 3 seconds, then for 10 seconds from the gas pulse generator to obtain the ozone into the reaction chamber, followed by rinsing for 10 seconds. Thus, the growth rate of the deposited metal oxide layer begins to increase immediately as the nitrogen concentration increases, and reaches a first peak when the nitrogen concentration reaches about 110 ppm (as seen in a close-up view of Figure 11, which shows the pattern of Figure 12). The leftmost part of the), and begins to slowly decrease as the nitrogen concentration increases further. Again, the uniformity (NU %) was improved and reached its optimum value at a nitrogen concentration of about 110 ppm. Figure 12 shows the increased N ₂ concentration additional impact; First, an increase in N ₂ to about 4000 ppm range, reduced thickness and uniformity decreases, but then, at increased N ₂ concentration trend itself be reversed at 24000 ppm of The vicinity of N ₂ is significantly flattened. The N ₂ concentration can be adjusted to achieve the desired effect based on the desired effect on the growth rate and uniformity of the deposited layer. Figure 13 shows the use of similar methods HfCl ₄ precursor and process parameters of the different figures, but exhibit growth rate and uniformity of supply to the ozone generator feed flow rate of N ₂ gas is concerned. As can be seen in the graph, increasing the N ₂ flow causes a substantial increase in the growth rate of the deposited yttria layer and its uniformity is improved.

Experiments using other ALD precursor chemistries also demonstrate an improvement in the deposition of metal oxides as the nitrogen feed gas concentration increases in the ozone generator. Figure 14 illustrates an improved graph showing the thickness and uniformity (NU%) of the deposited yttria film as the amount of nitrogen fed gas supplied to the ozone generator increases in the ALD process. The precursor used in this case is the rare earth cyclopentadienyl (Cp) compound La(iPrCp) ₃ .

Additional tests were performed to determine whether the metal oxide layer growth was caused by the chemical action of HfCl ₄ and TMA precursors when the strong oxidant N ₂ O was used alone as the oxidant gas in the ALD process. N ₂ O gas is not supplied from the ozone generating device, but is supplied from the gas cylinder, and no growth is observed in this configuration regardless of the temperature used during the ALD method. However, the active NO compound formed during ozone generation is effective for producing a uniform layer growth as described above.

It has been determined that various nitrogen compounds derived from exposure of oxygen and nitrogen to a plasma source result in an active compound that enhances the growth rate and uniformity of the thin film deposition process. The specific expression of the present invention utilizes nitrogen and oxygen compounds (specifically, excited N-O species obtained by exposing a component gas to a plasma source) to achieve uniform growth of the metal oxide layer in the ALD process. It is also known to those skilled in the relevant art that the use of an excited N-O species can also be used in other types of deposition methods described above.

In one embodiment, the methods and systems of the present invention utilize ions and active species containing a nitrogen-oxygen compound in the form of a free radical (referred to herein as an active N _x O _y species, where "x" and "y" may include any A suitable integer) of the activating gas enhances the deposition of the thin film metal oxide comprising the rare earth oxide. After the substrate has been exposed to the ALD precursor pulse/flush cycle in the reactor, ions/radicals in the gas are introduced into the reactor with the substrate during the oxidation pulse in the presence or absence of additional oxidant such as ozone . The introduced gas is allowed to contact the material to be treated, so that the desired reaction occurs. In a specific performance, in the case where the presence or absence of an additional oxidizing agent is introduced by activating the N _x O _y species to oxidize the organic materials deposited metal layer or metal halide layer.

As used herein, "substrate" refers to any surface on which a film treatment is performed. For example, the substrate on which the process can be processed may consist of materials such as germanium, antimony oxide, germanium on insulator (SOI), carbon doped germanium oxide, tantalum nitride, germanium doped, antimony, arsenic. Gallium, glass, sapphire, or any other suitable material: such as metals, metal nitrides, metal alloys, or other conductive materials, printed organic or inorganic circuit boards or thin film ceramic substrates. In a preferred embodiment, the substrate comprises a semiconductor. The barrier layer, metal or metal nitride on the surface of the substrate comprises titanium, titanium nitride, tungsten nitride, tantalum and tantalum nitride. The substrate can be of any desired size, such as a wafer having a diameter of 200 mm or 300 mm, and can also be in the form of a rectangular or square plate.

As used herein, "pulsing" refers to the introduction of a quantity of a compound that is introduced into the reaction zone of the reaction chamber either intermittently or discontinuously. The amount of a particular compound within each pulse can vary over time, depending on the duration of the pulse. As explained more fully below, the duration of each pulse is selected depending on several factors, such as the volumetric capacity of the processing chamber used, the vacuum system to which it is attached, and the volatility/reactivity of its particular compound.

In one embodiment, a method for depositing a thin film on a substrate located within a reaction chamber is provided, the method comprising recycling an atomic layer deposition to the substrate, the cycle comprising: exposing the substrate to a precursor gas for a precursor pulse interval And removing the precursor gas; and exposing the substrate to an oxidant comprising an oxidant gas and a nitrogen-containing species gas for a time interval of oxidation pulses, and then removing the oxidant. The precursor gas may comprise any suitable metal, and various specific manifestations of the invention include one of such as Sc, La, Ce, Pr, Nd, Sm, Eu, Gd, Th, Dy, Ho, Er, Tm, Yb, and Lu or A precursor gas of various rare earth metals. The precursor gas may include any desired compound such as a metal compound, an organometallic compound or a metal halide compound including, but not limited to, hafnium tetrachloride (HfCl ₄ ); titanium tetrachloride (TiCl ₄ ); antimony pentachloride (TaCl ₅ ); lanthanum pentafluoride (TaF ₅ ); zirconium tetrachloride (ZrCl ₄ ); rare earth β-diketone compound containing La(THD) ₃ ) and (Y(THD) ₃ ; rare earth cyclopentadiene a compound of the formula (Cp) comprising La(iPrCp) ₃ ; a rare earth sulfhydryl compound comprising trimethyl sulfonium La (FAMD) ₃ ; a cyclooctadienyl compound containing a rare earth metal; an alkyl sulfhydryl compound comprising bismuth-B Methyl-methylamino hydrazine (TEMAHf), hydrazine (diethylamino) hydrazine ((Et ₂ N) ₄ Hf or TDEAH) and hydrazine (dimethylamino) hydrazine ((Me ₂ N) ₄ Hf or TDMAH); Alkoxide; cerium halide compound; cerium tetrachloride; cerium tetrafluoride; and cerium tetraiodide.

The oxidant gas can include any suitable oxidant and can include only nitrogen-containing species gases. The nitrogen-containing species gas may comprise activated ions or radical species comprising at least one of NO*, N ₂ O*, NO ₂ *, NO ₃ *, and N ₂ O ₅ *. Preferably, the oxidizing agent can be selected from the group comprising _{O, O 2, NO, N} 2 O, NO 2, NO 3, N 2 O 5, NO x, N x O y radical species, N _x O _y ionic species, N _x O _y molecular species and combinations thereof consisting of one or more gas combinations of ozone. It may be used various active concentration of ozone in the oxidizing gas, containing approximately 25 atomic percent to 5 atomic percent O _3. The oxidant gas may comprise molecules derived from a self-decomposition process, or activated ions or radical species, such as, but not limited to, decomposing N ₂ O ₅ * into products such as NO ₂ * and NO ₃ *.

The ozone used in the specific performance of the present invention can be produced by plasma discharge of a gas supplied with O ₂ and a nitrogen source gas, which may contain any gaseous source of N ₂ or nitrogen, such as NO, N ₂ O, NO _2, NO. ₃ and N ₂ O ₅ . In various manifestations, the output stream of ozone generator may comprise a nitrogen-containing species in a gas, the nitrogen-containing gas comprises molecular species N _x O _y species and / or excitation plus N _x O _y radical or ionic species, and the ozone generator the output of the inverter may include _{O 2, NO, N 2 O} , NO 2, NO 3, N 2 O 5, NO x, N x O y, O and mixtures thereof radical of two or more substances ₃ Wherein the mixture comprises from about 5 atomic percent to 25 atomic percent of O ₃ . Any desired flow rate can be used to produce ozone and N _x O _y species ratio, wherein the mixture containing N ₂ / O ₂ flow rate ratio of more than 0.001. The ratio of oxygen to nitrogen source gases may also affect other aspects of the ALD process, including the growth rate of the deposited film; film uniformity across the substrate; dielectric constant of the deposited film; refractive index of the deposited film; and deposited film The molecular composition. The output stream can include a mixture of gases produced by the self-decomposition process, such as, but not limited to, decomposing N ₂ O ₅ into products such as NO ₂ and NO ₃ .

The specific performance of the generator of the present invention can be adjusted by at least controlling the power input, oxygen gas input, or nitrogen input. In one embodiment, the power input controls the plasma, and the amount of power delivered to the plasma determines at least one of: a growth rate of the deposited film; a film uniformity across the substrate; a dielectric constant of the deposited film; The refractive index of the deposited film; and the molecular composition of the deposited film. Further provided is a method for adjusting the generation of an oxidant such as ozone to achieve a predetermined standard by exposing O ₂ and a nitrogen source gas to a plasma discharge; monitoring O ₃ generated by a plasma discharge and exciting N _a ratio of _x O _y species; and adjusting at least one of power input to the plasma discharge, case temperature, O ₂ flow rate, and flow rate of the nitrogen source gas. The standard can be selected as any suitable parameter for generator operation, including oxidant flow; oxidant/N _x O _y concentration ratio; active N _x O _y species concentration; active N _x O _y species ratio, wherein excitation N _{The x} O _y species gas contains a plurality of excited nitrogen-oxygen compounds; and a concentration of a specific reactive nitrogen-oxygen compound.

Specific manifestations of the invention may include additional precursor pulses and oxidant pulses in any combination. The method further includes exposing the substrate to the second precursor gas for a second precursor pulse interval, and then removing the second precursor gas; and after removing the second precursor gas, exposing the substrate to including the oxidant gas and the nitrogen The oxidant of the species gas oxidizes the pulse interval and then removes the oxidant. In general, the method of the present invention comprises depositing a metal oxide in at least one of any thin film stack using a metal halide precursor and an oxidant comprising ozone and a nitrogen-oxygen species. The metal oxide may include, for example, at least one of Al ₂ O ₃ , HfO ₂ , ZrO ₂ , La ₂ O _{3 ,} and Ta ₂ O ₅ . Metal halides include any of the compounds in combination with any halide element.

The ALD cycle can be repeated any number of times to achieve any desired target such as a predetermined layer thickness. The number of repetitions of the precursor sequence for each ALD cycle may also vary, as may the ratio of the number of executions of the first precursor gas sequence to the number of executions of the second precursor gas sequence per ALD cycle may also vary.

Pulse intervals for exposing various gases to the substrate can be selected to meet any desired process criteria, such as deposited layer growth rate or cycle flow time. In one embodiment, the first precursor pulse interval is in the range of 300 milliseconds to 5 seconds; the first oxidation pulse interval is in the range of 50 milliseconds to 10 seconds; and the second precursor pulse interval is in the range of 500 milliseconds to 10 seconds. Within the range; and the first oxidation pulse interval is in the range of 50 milliseconds to 10 seconds. In a preferred embodiment, the first precursor pulse interval is in the range of 1 second to 2 seconds; the first oxidation pulse interval is in the range of 50 milliseconds to 2 seconds; and the second precursor pulse interval is between 1 second and 4 seconds. Within the range; and the first oxidation pulse interval is in the range of 50 milliseconds to 2 seconds.

Gas and reaction by-products can be removed from the reaction chamber using any desired technique. In one example, the method of removing the precursor gas and the oxidant gas includes introducing a flushing gas into the reaction chamber for a predetermined rinsing period, wherein the rinsing gas includes argon, nitrogen, helium, hydrogen, forming gas, helium, and neon. At least one gas; and the rinsing period can be selected to be in the range of about 3 seconds to 10 seconds. In an alternative embodiment, the rinse period is in the range of 500 milliseconds to four seconds. In one embodiment, the method of removing one or more of the precursor gas and the oxidant gas can include evacuating the air from the reaction chamber over a predetermined evacuation period.

The electronic device can be manufactured by a method consistent with the present invention. Such devices include capacitors, transistors, FLASH memory cells, and DRAM memory cells that are either formed as individual components or formed in a semiconductor or other substrate. The electronic device can include a metal oxide dielectric layer and a conductive layer in communication with the dielectric layer, the dielectric layer being deposited in the film by applying an ALD cycle to the substrate in the manner described herein.

Also presented is a system more fully described below, the system comprising: a reaction chamber; a source of precursor reactants connected to the reactor chamber; a source of flushing gas coupled to the reactor chamber; an oxidant source coupled to the reactor chamber; A source of excited nitrogen species to the reactor chamber; and a system operation and control mechanism, wherein the system is configured to perform the steps of any of the methods described herein. The description of the present invention is intended to be illustrative and not restrictive.

Exemplary embodiments of the present invention will now be described in detail with reference to the exemplary embodiments illustrated in the drawings.

The specific performance of the present invention provides a variety of methods for preparing films for use in a variety of applications, particularly for depositing high-k dielectric materials and barrier materials for use in the fabrication of transistors, capacitors, and memory cells. The methods include depositing a metal oxide thin film layer on a substrate using an atomic layer deposition (ALD) method.

The material deposited in the film during the ALD deposition of the present invention can be any desired material, such as a dielectric material, a barrier material, a conductive material, a nucleating/seeding material, or a bonding material. In one embodiment, the deposited material can be a dielectric material containing oxygen and at least one additional element such as ruthenium, rhodium, iridium, osmium, titanium, aluminum, zirconium, or combinations thereof, and in preferred embodiment The deposited material includes metal oxides, and more specifically includes rare earth metal oxides. In additional specific embodiments, the dielectric material may contain yttria, zirconia, yttria, alumina, yttria, titania, yttria, tantalum nitride, nitrogen oxides thereof (eg, HfO _x N _y ), Its bismuth salt (for example, HfSi _x O _y ), its aluminate (for example, HfAl _x O _y ), its bismuth oxynitride (for example, HfSi _x O _y N _z ), and combinations thereof. The dielectric material may also contain multiple layers of different compositions. For example, a build-up film can be formed by depositing a ruthenium oxide layer to a ruthenium oxide layer to form a ruthenium ruthenate material.

In one embodiment, the method and system of the present invention utilizes an activation gas containing ions and active species of a nitrogen-oxygen compound in a free radical form (hereinafter referred to as an active N _x O _y species) to enhance the inclusion of rare earth oxides. Deposition of thin film metal oxides. In a specific performance, it may be with the oxidizing agent such as ozone in the ALD process during the pulse after the pulse of the metal precursor to N _x O _y species provided on the substrate.

Commercially available ozone delivery systems, such as the ozone delivery systems used in conjunction with the ALD method, generally rely on dielectric barrier discharges and typically utilize nitrogen fed into the gas to provide consistent ozone production. Through a series of complex plasma reactions, various N _x O _y species can also be formed by O ₂ in the presence of N ₂ in the corona. Although these species at various concentrations in the effluent produced, but not the only measure to actively control and adjust the delivery system O ₃ concentrations.

Several ALD methods using ozone are extremely sensitive to the conditions of ozone production. For example, the wide response in HfO ₂ deposition rate and film uniformity is experimentally observed to be related to the O ₂ :N ₂ feed gas ratio, and cross-flow thermal ALD reactor HfCl ₄ /O ₃ ALD (using pure O ₃ ) The reactor temperature in the process has a window of view between the low reactor temperatures (200-250 ° C). At higher temperatures (eg, 300 ° C), a uniform HfO ₂ layer was obtained via the addition of N ₂ during O ₃ production via experiments, as shown in FIG. These experimental results support the hypothesis that although the reactive species in ozone-based ALD may be exclusively O ₃ , the N _x O _y species also contributes at 300 °C.

Therefore, studies were conducted to first characterize (from the ozone delivery system) gaseous species entering and leaving the ALD reactor using FTIR, which is related to the O ₂ :N ₂ feed gas ratio, the O ₃ concentration, and the generator power level. N ₂ O ₅ and N ₂ O are detected at the outlet of the O ₃ delivery unit having a N ₂ :O ₂ feed gas, as shown in FIG. The life of the O ₃ and N _x O _y species has been investigated in relation to reactor temperatures and coating materials (HfO ₂ , Al ₂ O _{3 ,} etc.). The FTIR analysis of the reactor effluent during the half reaction of ozone with absorbed HfO ₂ -HfCl ₃ was used to elucidate the effect of the N _x O _y species on HfO ₂ deposition. The ALD deposition rate, film uniformity, and various volume and electrical film properties of HfO ₂ deposited under various ozone transport conditions were determined based on FTIR and the theory surrounding the effect of O ₃ and N _x O _y species on potential reaction pathways. Accordingly, the present invention comprises a specific performance has improved over the layer of ALD deposition thickness and uniformity when used as an additional output from the ozone generated in the reaction chamber is introduced to various molecules and excitation of N _x O _y species.

Referring to Figure 1, presents a method 100 for using a compound such as an activated gas species of N _x O _y thin film of metal oxide is deposited. At the beginning of method 100 (105), the substrate is placed in a reaction chamber and heated to a predetermined temperature. The predetermined temperature may include any desired temperature, and the specific performance of the present invention may include a temperature such as about 130 ° C to 300 ° C. During execution of method 100, the reaction chamber is maintained at any desired pressure range (such as from about 1 mTorr to about 200 Torr), and in one particular embodiment of the invention is from about 2 Torr to 6 Torr, and another specific In the performance, it is about 3 Torr to 4 Ton, and in yet another preferred embodiment, the reaction chamber pressure is maintained at about 3.5 Torr.

The carrier gas can be supplied to the reaction chamber continuously or intermittently and can be used to distribute the precursor product, the reaction product, and the oxidation product, or to flush residual gases or reaction by-products from the reaction chamber. Suitable carrier gases or flushing gases may comprise argon, nitrogen, helium, hydrogen, forming gases, or combinations thereof.

After the (105) ALD process is initiated, the precursor gas is pulsed (110) into the reaction chamber in the presence or absence of a carrier gas. The precursor gas may include any desired compound such as a metal compound, an organometallic compound or a metal halide compound including, but not limited to, hafnium tetrachloride (HfCl ₄ ); titanium tetrachloride (TiCl ₄ ); antimony pentachloride (TaCl ₅ ); lanthanum pentafluoride (TaF ₅ ); zirconium tetrachloride (ZrCl ₄ ); rare earth β-diketone compound containing (La(THD) ₃ ) and (Y(THD) ₃ ); rare earth cyclopentane a dienyl (Cp) compound comprising La(iPrCp) ₃ ; a rare earth sulfhydryl compound comprising tetramethyl ruthenium (FAMD) ₃ ; a cyclooctadienyl compound comprising a rare earth metal; an alkyl guanamine compound, comprising肆-ethyl-methylamino hydrazine (TEMAHf), hydrazine (diethylamino) hydrazine ((Et ₂ N) ₄ Hf or TDEAH) and hydrazine (dimethylamino) hydrazine ((Me ₂ N) ₄ Hf or TDMAH); alkoxide; bismuth halide compound: ruthenium tetrachloride, ruthenium tetrafluoride and ruthenium tetraiodide.

During a gas pulse as referred to herein, the substrate in the reaction chamber is exposed to the supply gas for a predetermined period of time, and this period is referred to herein as a pulse interval. The pulse interval for providing the precursor gas to the substrate can be predetermined to any desired time, for example, can include a time in the range of about 300 milliseconds to 5 seconds, and in a particular performance, the pulse interval is in the range of 1 second to 3 seconds. .

After the substrate has been exposed to the precursor gas for a predetermined pulse interval, the precursor gas is flushed (120) from the reaction chamber by supplying a purge gas and/or by evacuating or withdrawing. The rinsing time or time at which the rinsing gas is supplied to the reaction chamber to displace and/or remove other gases or reaction products may be selected to be any desired time, such as about 3 to 10 seconds, and may be about 500 in some specific performances. Milliseconds to 5 seconds.

The activated N _x O _y species gas as defined above is introduced into the (130) reaction chamber, and in one embodiment, the oxidation step is initiated by introducing an activated N _x O _y species in the presence or absence of an additional oxidant ( 110) A layer of precursor material deposited. During step (130), a combination of oxidant/oxidant gas or oxidant/oxidant gas may be supplied to the reaction chamber simultaneously or sequentially to react with the first precursor. The N _x O _y species gas may also be introduced in the presence or absence of a carrier gas such as nitrogen N ₂ and may be further introduced in combination with an oxidant gas or oxidant gas mixture. As previously stated, the N _x O _y species may include any activated, ionic or free radical NO compound such as activated nitrous oxide (N ₂ O*), nitric oxide (NO*), nitrous oxide (N _{2 )} O ₅ *) or nitrogen dioxide (NO ₂ *). The N _x O _y species gas can be produced in any desired manner, and in a particular manifestation, the N _x O _y species is produced from ozone supplied with O ₂ , N ₂ , N ₂ O, NO, NH ₃ or any nitrogen-containing molecule. The device is produced by plasma discharge in which the concentration of nitrogen-containing molecules is greater than 5 sccm/2000 sccm or 2000 ppm. In another specific embodiment, in the reaction chamber, in the presence of any desired feed gas, by means of an inductive coupling method, an ECR (electron cyclotron resonance) method, a capacitive coupling method, or a direct plasma method. An N _x O _y species is produced or a N _x O _y species is supplied to the reaction chamber. In yet another embodiment, a nitrogen-oxygen gas such as NO or N ₂ O is fed to a corona discharge (such as provided by an ozone generator) without additional oxygen (or remote or direct plasma) Source) to produce N _x O _y species. Additional N ₂ may be provided to the corona discharge or plasma source along with the nitrogen-oxygen gas. In yet another embodiment, a stoichiometric amount of N ₂ +O _{2 is} provided to a corona discharge or plasma source to produce N _x O _y * (eg, NO radicals).

In the ALD method of the present invention, any desired oxidizing gas may be used in any step, and such oxidizing gas may include oxygen (O ₂ ), ozone (O ₃ ), atomic oxygen (O), water (H ₂ O). ), hydrogen peroxide (H ₂ O ₂ ), nitrous oxide (N ₂ O), nitric oxide (NO), dinitrogen pentoxide (N ₂ O ₅ ), nitrogen dioxide (NO ₂ ), derived therefrom Or a combination thereof. In a preferred embodiment, the oxidizing gas is an ozone/oxygen (O ₃ /O ₂ ) mixture such that the ozone concentration is between about 3 atomic percent of O ₃ to about 25 atomic percent of O ₃ of the O ₃ /O ₂ mixture. Within the scope. In one embodiment, wherein the N _x O _y species is introduced simultaneously with an oxidant such as an ozone/oxygen (O ₃ /O ₂ ) mixture, the N _x O _y species may be present as greater than 1% by volume of the oxidizing fluid. In an alternative preferred embodiment, the oxidizing gas to which the N _x O _y species gas is added is an ozone/oxygen (O ₃ /O ₂ ) mixture such that the ozone concentration is about 12 atomic percent of the O ₃ /O ₂ mixture. O ₃ to about 18 atomic percent of O ₃ .

The N _x O _y /oxidant step (130) is continued for a predetermined pulse interval, and its duration may be any suitable time range, such as about 50 milliseconds to 10 seconds, and in another specific manifestation, the first oxidation pulse interval It is in the range of 50 milliseconds to 2 seconds. Then, (140) N _x O _y gas or N _x O _y / oxidant gas is flushed from the reaction chamber by supplying a flushing gas or by evacuating or withdrawing. The rinse time can be selected to any suitable time, such as about 3-10 seconds, and can be about 500 milliseconds in some specific performances.

Once the N _x O _y species gas or N _x O _y / oxidant gas has been flushed from the reaction chamber, the method 100 of Figure 1 is continued, wherein it is determined (150) whether the sequence is to be repeated (160). This decision can be made based on any required criteria. For example, the determination can be made based on the number of precursor gas pulse sequences that require a particular concentration, thickness, and/or uniformity of the deposited material to be achieved. This decision can also be made in the context of incorporating another specific manifestation of the plurality of precursors/rinsing steps prior to the N _x O _y pulse step reaching the desired precursor ratio, particularly in the following specific manifestations, wherein prior to exposure to N _x O _y species plurality of different precursor applied to a substrate to achieve a desired substrate such as a ternary metal oxide. For example, in any order, the ruthenium containing precursor can be used in one precursor pulse and the ruthenium containing precursor is used in another precursor pulse to produce an HfLaO oxide layer after the N _x O _y pulse step. Method 100 is repeated (160) until a predetermined criterion is met, after which the method ends (155).

2 schematically illustrates an exemplary embodiment of a thin film processing system 200 including a reaction chamber, the reaction chamber further comprising means for maintaining a substrate (not shown) under predetermined pressure, temperature, and environmental conditions for selectivity A mechanism for exposing a substrate to various gases. The precursor reactant source 220 is coupled to the reaction chamber by a conduit or other suitable mechanism 220A and may be further coupled to a manifold, valve control system, mass flow control system, or other mechanism to control gaseous precursors from the precursor reactant source 220. . The precursor (not shown) is supplied from a precursor reactant source 220, which may be liquid or solid at room temperature and standard atmospheric pressure conditions. Such precursors can be vaporized in a reactant source vacuum vessel that can be maintained at or above the evaporation temperature within the precursor source chamber. In such specific manifestations, the vaporized precursor can be transported with a carrier gas (eg, an inert or inert gas) and then fed into the reaction chamber 210 via conduit 220A. In other embodiments, the precursor can be a vapor under standard conditions. In such specific manifestations, the precursor does not need to evaporate and a carrier gas may not be needed. For example, in one particular implementation, the precursor can be stored in a gas cylinder.

Purge gas source 230 is also connected to the reaction chamber 210, and optionally various rare gas or an inert gas supplied to the reaction chamber 210 to facilitate removal of the precursor gas from the reaction chamber, the oxidant gas, N _x O _y species or waste gas. The various inert or rare gases that can be supplied can come from solid, liquid or stored gaseous forms. The oxidant/N _x O _y species source 240 connects 240A to the reaction chamber 210 and is coupled to the reaction chamber via a conduit or other suitable mechanism 220A and can be further coupled to a manifold, valve control system, mass flow control system, or other mechanism for control A gaseous oxidant/N _x O _y species gas from precursor reactant source 220.

The oxidant/N _x O _y species source 240 produces ozone and N _x O _y species via any desired mechanism and any desired feed gas, the oxidant/N _x O _y species source 240 comprising a conventional ozone generator, directly Or a remote plasma generator, etc. 4 illustrates a particular representation of an oxidant/N _x O _y species source 240 of the present invention in which an output stream 240A comprising N _x O _y species is generated from a plasma discharge from a generator 430, from a connection 420 to a generator. The oxidant source 410 of 430 supplies an oxidant such as O ₂ , and the nitrogen source 430 connects 440 to the generator 430 and supplies N ₂ , N ₂ O, NO, NH ₃ or any nitrogen-containing molecule. Generator 430 may further include an ozone generator such as a DBD generator, or a generator utilizing any remote or direct plasma activation method such as inductive coupling, ECR (electron cyclotron resonance), or capacitive coupling.

In an alternative specific representation (not shown), N _x O _{y is} produced by feeding a nitrogen-oxygen gas such as NO or N ₂ O to the corona discharge at generator 430 in the absence of additional oxidant. Species. Additional N ₂ may be provided to generator 430 along with the nitrogen-oxygen gas. In yet another specific manifestation, stoichiometric N ₂ +O _{2 is} provided to generator 430 to produce N _x O _y * (eg, NO radicals).

Sensor 450 may be used to monitor the amount of the oxidizing agent and the N _x O _y species generated by the generator 430, the composition and / or concentration. Sensor 450 can include any suitable hardware, mechanism, or software to detect the presence of a desired N _x O _y radical or ionic species and/or oxidant, and in various embodiments the sensor 450 can include Fourier A sensor for converting an infrared spectrum analyzer, a UV absorption sensor, a density sensor, a conductivity/capacitance sensor, a chemiluminescence sensor, or a gas tomography sensor. The sensor 450 can be further coupled to an N _x O _y species generator control 460 that configures the generator 430, the oxidant source 410, the nitrogen source 430, and an optional carrier gas source (not shown) via various user or automation inputs 470. The N _x O _y species and other gases of the desired composition and volume are produced in output stream 240A. In some embodiments, such other gases may comprise an oxidant such as a desired ratio of O ₂ /O ₃ or other gases. By way of example, but not limitation, generator control 460 can modulate to a power input (not shown) of generator 430 to alter the composition of each type of activated or free NO compound in gaseous output stream 240A. Since the sensor 450 is coupled to the generator 430 and/or its output stream 240A and is configured by the control 460 to receive a signal from the sensor 450 indicating the change in composition and volume of the output stream 240A, the software can be utilized by the software And/or the electronic hardware performs closed loop control to operate the electrical control or pneumatic control valve to control the nitrogen source gas, the oxidant source gas, the carrier gas or other gases in addition to controlling the power and/or frequency input to the generator 430. Flow to achieve the desired output gas composition comprising the N _x O _y species.

2 also illustrates system operation and control mechanism 260 that provides electronic circuitry and mechanical components to selectively operate valves, manifolds, pumps, and other devices included in system 200. Such circuits and components operate to introduce precursors, purge gases, oxidant/N _x O _y species from respective precursor sources 220, purge gas source 230, and oxidant/N _x O _y sources into reaction chamber 210. The system operation and control mechanism 260 also controls the timing of the gas pulse sequence, the temperature of the substrate and reaction chamber, and the pressure of the reaction chamber and various other operations necessary to provide normal operation of the system 200. Operation and control mechanism 260 may include a control software and electrical or pneumatic control valve to control the inflow and outflow of the reaction chamber 210 precursors, reactants, oxidants, N _x O _y species and flow of flushing gas. In a particular embodiment that is particularly suitable for an ALD reactor, the operation and control mechanism 260 also controls the flow of process gas flowing into the reaction chamber 210 to form the surface to ALD, such as by forming a protective layer on the inner surface of the reaction space. Reaction passivation. In the surface after passivation, the load control system of the substrate such as silicon wafer to the chamber 210, and so the precursor was 210 deposit on the substrate to form the oxidant, N _x O _y species and / or a purge gas into the chamber. The control system can include modules such as software or hardware components (eg, FPGAs or ASICs) that perform certain tasks. The module can advantageously be configured to reside on an addressable storage medium of the control system and configured to perform one or more processes.

It will be apparent to those skilled in the art that there may be other configurations of the inventive system comprising different amounts and types of precursor reactant sources, flushing gas sources, and/or oxidant/N _x O _y sources. In addition, such techniques will also appreciate that there are many arrangements of valves, conduits, precursor sources, purge gas sources, carrier gas sources, and/or oxidant sources that can be used to selectively feed gas into the reactor reaction. The purpose in chamber 210. Moreover, as a schematic representation of a thin film processing system, many of the components are omitted for simplicity of illustration, and such components can include, for example, various valves, manifolds, purifiers, heaters, vessels, vents, and/or bypasses. .

3A shows a schematic of a specific example of an alternative processing system 200, wherein the oxidant / reactant source 340 is connected to the reaction chamber 210 340A, N 360A and is also connected to the reaction chamber 360 _x O _y species source separation. Via this configuration, operation and control system 260 may be incorporated independently N _x O _y species-containing gas into the reaction chamber 210, and since the oxidizer / reactant source 340 or other oxidant introduced into the reaction product. With this configuration, an oxidant, an N _x O _y species gas, or a combination of the two, can be applied to the reaction chamber to achieve a particular layer deposition effect. In one exemplary embodiment, the oxidizing agent and can be applied to species containing alternating pulses _y N _x O gases in the metal oxide thin film on a substrate within a reaction chamber 210 for enhanced deposition or growth rate uniformity.

3B shows schematically a further specific example of the processing system 200, wherein the oxidizer / reactant source 340 is connected to the reaction chamber 340A 210 and 390 separated with integrated N _x O _y species source 210 within the reaction chamber. Pipes and connections are not illustrated, which supply various source feed gases, such as oxygen or nitrogen containing gases, to the N _x O _y species source 390 or to their output connections, which will contain N _{The x} O _y species gas is supplied to the substrate located in the reaction chamber 210. 200. Similar to the illustration of a system illustrated in FIG. 3A, the operation and control system 260 may be incorporated independently N _x O _y species-containing gas into the reaction chamber 210, and since the oxidizer / reactant source 340 or other oxidant introduced into the reaction . Also via this configuration, an oxidant, an N _x O _y species gas, or a combination of the two, can be applied to the reaction chamber to achieve a particular layer deposition effect. In one exemplary embodiment, the oxidizing agent and may be applied alternating pulses containing species gases _y N _x O, to the metal oxide thin film on a substrate within the reaction chamber 210 to obtain an enhanced deposition rate or uniformity of growth

Figure 6 illustrates a single metal oxide (MOS) transistor 600 fabricated by the specific representation of the method of the present invention to form a dielectric layer 620 comprising an ALD-deposited gate insulator layer. The use of high-k dielectrics such as HfO ₂ , ZrO ₂ , La ₂ O ₃ and Ta ₂ O ₅ , HfLaO and HfZrO deposited via the methods and systems of the present invention provides for the manufacture of smaller and smaller transistors, The transistors have improved leakage current and other characteristics compared to conventional yttria-type dielectrics. Substrate 605 is prepared for deposition, typically for depositing tantalum or niobium containing materials. However, as described above with respect to the type of substrate, other semiconductive materials such as a germanium substrate, a gallium arsenide substrate, and a germanium-sapphire substrate may also be used. Prior to deposition of the gate dielectric 620, various layers within the substrate 605 of the transistor are formed and various regions of the substrate, such as the drain diffusion 610 and the source diffusion 615 of the transistor 600, are prepared. Substrate 605 is typically cleaned to provide an initial substrate that depletes its original oxide. The substrate can also be cleaned to provide a hydrogen end face to improve the chemisorption rate. The ordering of the regions of the transistor being processed may follow the typical ordering typically performed in the fabrication of MOS transistors, as is known to those skilled in the art.

In various embodiments, the dielectric 620 covering the region between the source diffusion region 615 and the drain diffusion region 610 on the substrate 605 is deposited by the ALD method according to FIG. 1 of the present invention, and includes at least Partially exposed to a molecularly proportioned metal oxide layer deposited by a gas containing N _x O _y species. The illustrated single dielectric layer 620 is only one specific representation, and may include, in other embodiments, additional thin film metal oxide layers or other suitable dielectric or barrier material layers deposited in accordance with the specific embodiments of the present invention. .

The transistor 600 has a conductive material that forms a single gate electrode 625 on the gate dielectric 620. Generally, forming the gate 625 can include forming a polysilicon layer, although an alternative method can be used to form the metal gate. Fabrication of substrate 605, source region 615, and drain region 610 and gate 625 are performed by standard methods known to those skilled in the art or enhanced by the specific performance of the present invention. In addition, the ordering of the various elements of the method for forming the transistor is carried out using standard manufacturing methods, as is known to those skilled in the art.

In the particular representation of the illustration, dielectric layer 620 is illustrated as a first layer and is in direct contact with substrate 605; however, the invention is not limited thereto. In various embodiments, a diffusion barrier layer can be interposed between the dielectric layer 620 and the substrate 605 to prevent metal contamination from affecting the electrical characteristics of the device. Although the transistor 600 illustrated in FIG. 6 has a conductive material that forms a single gate electrode 625, the gate dielectric can also be used in a floating gate device, such as the flash memory illustrated in FIG.

Figure 7 illustrates a single memory cell 700 fabricated in accordance with one particular embodiment of the present invention. In this particular representation, memory unit 700 is a floating gate memory unit suitable for use in a FLASH memory device or other memory device. Similar to the transistor 600 illustrated in FIG. 6, the memory cell 700 includes a substrate 705 (typically germanium, but may be other substrates as described herein) in which a source region 715 and a drain region are formed. 710. In general, the memory cell 700 also includes a first dielectric layer 720 (which may be referred to as a tunneling layer), a storage element or floating gate 725 (formed of a conductive material such as polysilicon), a second dielectric layer 725, and a control gate. A pole 735 (also formed of a conductive material such as polysilicon).

Similar to the transistor 600 described in connection with FIG. 6, the memory cell 700 is fabricated using the specific representation of the method of the present invention to form the dielectric layer 720 or the dielectric layer 730 or both. Dielectric layer 720, dielectric layer 730 may be fabricated in whole or in part by using an ALD-deposited metal oxide gate insulator layer formed by the method in accordance with the present invention. Substrate 705 is prepared for deposition, typically for depositing tantalum or niobium containing materials. However, as described above with respect to the type of substrate, other semiconductive materials such as a germanium substrate, a gallium arsenide substrate, and a germanium-sapphire substrate may also be used. Prior to deposition of the dielectric 720, various layers within the substrate 705 of the transistor are formed, and various regions of the substrate, such as the drain diffusion 710 and the source diffusion 715 of the memory cell 700, are prepared. The substrate substrate 705 is typically cleaned to provide an initial substrate that depletes its original oxide. The substrate can also be cleaned to provide a hydrogen end face to improve the chemisorption rate. The ordering of the regions of the transistor being processed may follow the typical ordering typically performed in the fabrication of MOS transistors, as is known to those skilled in the art.

In various embodiments, the dielectric 720 covering the region between the source diffusion region 715 and the drain diffusion region 710 on the substrate 705 is deposited by the ALD method according to FIG. 1 of the present invention, and includes at least Partially exposed to a metal oxide layer deposited by a gas containing N _x O _y species. In other embodiments, the illustrated dielectric layer 720, dielectric layer 730 may also include additional metal oxide layers or other suitable dielectric or barrier material layers.

The memory cell 700 has a conductive material that forms a control gate electrode 735 and a floating gate 725 in a region on the dielectric 720. Generally, forming gate 725, gate 735 can include forming a polysilicon layer, although alternative methods can form a metal gate. The method of fabricating substrate 705, source region 715 and drain region 710, gate 725, and gate 735 is performed using standard methods known to those skilled in the art. Additionally, the ordering of the various elements of the method for forming a memory cell is performed using standard manufacturing methods, as is known to those skilled in the art.

In the specific representation of the figure, the dielectric layer 720 and the dielectric layer 730 are illustrated as directly contacting the substrate 705, the floating gate 725, and the control gate 735. In other specific implementations, the diffusion barrier layer can be interposed between the dielectric layer 720, the dielectric layer 730 and/or the substrate 705, the floating gate 725, and the control gate 735 to prevent metal contamination from affecting the electrical characteristics of the memory cell 700. .

The specific expression of the method for forming the metal oxide dielectric layer according to the present invention can also be applied to methods for fabricating various integrated circuits, memory devices, and capacitors in electronic systems. In a particular embodiment for fabricating a capacitor, the method includes forming a first conductive layer, forming a dielectric layer comprising a metal oxide layer on the first conductive layer by the specific representation of the ALD cycle described herein, and dielectrically A second conductive layer is formed on the layer. The ALD formation of the metal oxide dielectric layer allows the dielectric layer to be designed within a predetermined composition that provides the desired dielectric constant and/or other controllable features.

Electronic components such as transistors, capacitors, and other devices having dielectric layers fabricated from the specific embodiments of the invention described herein can be implemented in memory devices, processors, and electronic systems. In general, such an electronic component 810 can be incorporated into a system 820, such as an information processing device, as illustrated in FIG. Such information processing devices may include wireless systems, telecommunications systems, mobile subscriber units such as cellular and smart phones, personal digital assistants (PDAs), and computers. Figure 9 illustrates a specific representation of a computer having a dielectric layer (such as a HfLaO dielectric layer) formed by atomic layer deposition using the methods described herein, and is described below. Although certain types of memory devices and computing devices are shown below, those skilled in the art will appreciate that several types of memory devices and electronic systems including information processing devices utilize the subject matter.

The personal computer 900 illustrated in FIG. 9 can include an output device (such as a screen or monitor) 910, a keyboard input device 905, and a central processing unit 920. Central processing unit 920 can generally include a circuit 925 that utilizes processor 935 and a memory bus circuit 937 that connects one or more memory devices 940 to processor 935. Processor 935 and/or memory 940 of personal computer 900 also includes at least one transistor or memory unit having atomic layer deposition using methods described herein in accordance with the specific teachings of the present subject matter. A dielectric layer is formed. Those skilled in the art understand that other electronic components of the computer 900 may be utilized using the methods described herein a dielectric layer formed by atomic layer deposition, a dielectric layer such as is formed by at least partially exposed to N _x O _y species-containing gas . Such components may include many types of integrated circuits including processor chipsets, video controllers, memory controllers, I/O handlers, BIOS memory, FLASH memory, audio and video processing chips, and the like. Those skilled in the art will also appreciate that other information processing devices (such as personal digital assistants (PDAs)) and mobile communication devices (such as cellular phones and smart phones) may have a dielectric formed by using the specific performance of the present invention. Floor.

While a preferred embodiment of the invention has been described, it is understood that the invention is not limited thereto, and may be modified without departing from the invention. The scope of the invention is defined by the scope of the appended claims, and all means, processes and methods in the meaning of

100‧‧‧ method

105‧‧‧Steps

110‧‧‧Steps

120‧‧‧Steps

130‧‧‧Steps

140‧‧‧Steps

150‧‧‧ steps

155‧‧‧Steps

160‧‧‧Steps

200‧‧‧film processing system

210‧‧‧Reaction room

220‧‧‧Precursor reactant source

220A‧‧‧Institution/Pipeline

230‧‧‧ flushing gas source

230A

240‧‧‧Oxidant/N _x O _y species source

240A‧‧‧Output flow

260‧‧‧Control agency

340‧‧‧Oxidant/reactant source

340A‧‧‧ Connection relationship

360‧‧‧N _x O _y species source

360A‧‧‧ Connection relationship

390‧‧‧N _x O _y species source

410‧‧‧Oxiant source

420‧‧‧ Connection relationship

430‧‧‧ generator

440‧‧‧ Connection relationship

450‧‧‧Sensor

460‧‧‧N _x O _y species generator control

470‧‧‧ Input

500‧‧‧DBD ozone generator unit

505‧‧‧ gap

510A‧‧‧electrode

510B‧‧‧electrode

520A‧‧‧ dielectric materials

520B‧‧‧ dielectric materials

530‧‧‧Dry feed gas oxygen

550‧‧‧Ozone

560‧‧‧AC voltage source

600‧‧‧MOS transistor

605‧‧‧Substrate

610‧‧‧Bungan diffusion

615‧‧‧Source diffusion

620‧‧‧ gate dielectric layer

625‧‧‧gate electrode

700‧‧‧ memory unit

705‧‧‧Substrate

710‧‧‧Bungee area

715‧‧‧ source area

720‧‧‧First dielectric layer

725‧‧‧Storage components or floating gates

730‧‧‧Second dielectric layer

735‧‧‧Control gate

800

810‧‧‧Electronic components

820‧‧‧ system

900‧‧‧PC

905‧‧‧Keyboard input device

910‧‧‧output device

920‧‧‧Central Processing Unit

925‧‧‧ circuit

935‧‧‧ processor

937‧‧‧Memory Bus Bar Circuit

940‧‧‧ memory device

Figure 1 illustrates the process flow of a particular representation of the present invention.

Figure 2 shows an illustration of a thin film processing system of the present invention.

3A shows a diagram illustrating a thin film processing system according to the species and the oxidant having a separate source of O _y N _x invention.

Figure 3B shows an illustration of a thin film processing system of the present invention having a source of N _x O _y species in a reaction chamber.

Figure 4 illustrates a specific representation of the oxidant/N _x O _y species source of the present invention.

Figure 5 illustrates a simplified DBD ozone generator unit of the prior art.

Figure 6 illustrates a metal oxide transistor having a dielectric layer formed by a method consistent with the present invention.

Figure 7 shows a memory cell having at least one dielectric layer formed by a method consistent with the present invention.

Figure 8 illustrates a generalized system incorporating electronic components comprising a dielectric layer formed by methods consistent with the present invention.

Figure 9 shows an information processing device such as a computer having an electronic component comprising a dielectric layer formed by a method consistent with the present invention.

Figure 10 shows a graph illustrating the growth rate of HfO ₂ layer under various concentrations of nitrogen feed gas in an ozone generator.

Figure 11 shows a graph illustrating another experimental measured thickness and uniformity of yttrium oxide deposited as the nitrogen feed gas concentration is changing, and represents the leftmost portion of Figure 12.

Figure 12 shows a graph plotting the measured thickness and uniformity of yttrium oxide deposited as the nitrogen feed gas concentration is changing.

Figure 13 shows a graph plotting the measured thickness and uniformity of yttrium oxide deposited as the nitrogen feed gas flow is changing.

Figure 14 graphically illustrates an improvement in the thickness and uniformity of the yttria film deposited as the amount of nitrogen feed gas supplied to the ozone generator increases.

Figure 15 shows a graph illustrating the growth rate of HfO ₂ layer in an ozone generator having a comparative nitrogen/oxygen ratio at various concentrations of nitrogen feed gas.

Figure 16 illustrates the detection of N ₂ O ₅ and N ₂ O at the outlet of an O ₃ delivery unit having a N ₂ :O ₂ feed gas.

100. . . method

105. . . step

110. . . step

120. . . step

130. . . step

140. . . step

150. . . step

155. . . step

160. . . step

Claims (23)

A method for depositing a thin film on a substrate in a reaction chamber, the method comprising the steps of: applying an atomic layer deposition cycle to the substrate, the cycle comprising the steps of: exposing the substrate to a precursor gas for a precursor pulse interval, and then Removing the precursor gas; forming an active N _x O _y species; introducing the active N _x O _y species into the reaction chamber; exposing the substrate to an oxidant pulse interval including an oxidant gas and the active N _x O _y species, the oxidizing agent is then removed; and introduced into the reaction chamber prior to the active N _x O _y species, using sensors to monitor the activity of the N _x O _y species and one or more process adjustments based on the monitoring parameters. The method of claim 1, wherein the precursor gas comprises a component selected from the group consisting of Sc, La, Ce, Pr, Nd, Sm, Eu, Gd, Th, Dy, Ho, Er, Tm, Yb, Lu, and combinations thereof. Group of rare earth metals. The method of claim 1, wherein the precursor gas comprises at least one of an organometallic compound and a metal halide compound. The method of claim 1, wherein the precursor gas comprises at least one of: hafnium tetrachloride (HfCl ₄ ); titanium tetrachloride (TiCl ₄ ); antimony pentachloride (TaCl ₅ ); pentafluorocarbon TaF ₅ ; zirconium tetrachloride (ZrCl ₄ ); rare earth β-diketone compound containing (La(THD) ₃ ) and (Y(THD) ₃ ); rare earth cyclopentadienyl (Cp) compound , comprising La(iPrCp) ₃ ; a rare earth sulfhydryl compound comprising trimethyl hydrazine La (FAMD) ₃ ; a cyclooctadienyl compound containing a rare earth metal; an alkyl sulfhydryl compound comprising: hydrazine-ethyl-methylamine Base 铪 (TEMAHf); 肆 (diethylamino) hydrazine ((Et ₂ N) ₄ Hf or TDEAH); and 肆 (dimethylamino) hydrazine ((Me ₂ N) ₄ Hf or TDMAH); alkoxide a halogenated compound of cerium; cerium tetrachloride; cerium tetrafluoride; and cerium tetraiodide. The method of claim 1, wherein the oxidant gas comprises a nitrogen-containing species gas. The method of claim 1, wherein the active N _x O _y species comprises an activated ion or a radical species comprising NO*, N ₂ O*, NO ₂ *, NO ₃ * And at least one of N ₂ O ₅ *. The method of claim 1, wherein the oxidant gas comprises ozone and is selected from the group consisting of O, O ₂ , NO, N ₂ O, NO ₂ , NO ₃ , N ₂ O ₅ , N _x O _y radical species, N One or more gases of the group consisting of _x O _y ion species and combinations thereof. The method of claim 7, wherein the oxidant gas comprises from about 5 atomic percent to 25 atomic percent of O ₃ . The method of claim 7, wherein the O ₃ is made from O ₂ and a nitrogen source gas, wherein the mixture of the O ₂ and the nitrogen source gas is subjected to a plasma discharge. The method of claim 9, wherein the nitrogen source gas is at least one of N ₂ , NO, N ₂ O, NO ₂ , NO ₃ and N ₂ O ₅ . The method of claim 1, wherein the N _x O _y species comprises an excited N _x O _y radical species, an excited N _x O _y ion species, and combinations thereof. The method according to Claim 1 patentable scope, wherein the oxidant gas comprises _{O, O 2, NO, N} 2 O, NO 2, NO 3, N 2 O 5, NO x, N x O y, which is free radicals and O ₃ a mixture of two or more of the two, and wherein the mixture comprises from about 5 atomic percent to 25 atomic percent of O ₃ . The method of claim 10, wherein the N ₂ /O ₂ flow ratio is >0.001. The method of claim 10, wherein the ratio of the O ₂ and the nitrogen source gas determines at least one of: an amount of a nitrogen-containing species gas comprising an activated ion or a radical species, The activated ion or radical species comprises at least one of NO*, N ₂ O*, NO ₂ *, NO ₃ *, and N ₂ O ₅ *; the concentration of the nitrogen-containing species gas, the nitrogen-containing species gas including activated ions or a radical species, the activated ion or radical species comprising at least one of NO*, N ₂ O*, NO ₂ *, NO ₃ *, and N ₂ O ₅ *; growth rate of the deposited film; Film uniformity of the substrate; dielectric constant of the deposited film; refractive index of the deposited film; and molecular composition of the deposited film. The method of claim 10, wherein the power input controls the plasma, and the amount of power delivered to the plasma determines at least one of: an amount of a nitrogen-containing species gas comprising an activated ion or a radical species, the activated ion or radical species comprising at least one of NO*, N ₂ O*, NO ₂ *, NO ₃ *, and N ₂ O ₅ *; concentration of a nitrogen-containing species gas, the nitrogen-containing species The species gas includes an activated ion or a radical species, the activated ion or radical species comprising at least one of NO*, N ₂ O*, NO ₂ *, NO ₃ *, and N ₂ O ₅ *; Growth rate; film uniformity across the substrate; dielectric constant of the deposited film; refractive index of the deposited film; and molecular composition of the deposited film. The method of claim 10, further comprising the steps of: generating the oxidant by exposing the O ₂ and nitrogen source gases to a plasma discharge; monitoring O ₃ generated by the plasma discharge and exciting N _x O _y a ratio of species; and adjusting at least one of a power input of the plasma discharge, a temperature of the outer casing, a flow rate of the O ₂ , and a flow rate of the nitrogen source gas to achieve a predetermined standard. The method of claim 16, wherein the predetermined standard comprises at least one of: an oxidant flow rate; an oxidant/N _x O _y concentration ratio; an active N _x O _y species concentration; a ratio of active N _x O _y species, Wherein the excited N _x O _y species gas contains a plurality of excited nitrogen-oxygen compounds; and a concentration of the specific active nitrogen-oxygen compound. The method of claim 1, further comprising the steps of: exposing the substrate to a second precursor gas for a second precursor pulse interval, then removing the second precursor gas; and removing the second precursor gas Thereafter, the substrate is exposed to an oxidant comprising an oxidant gas and a nitrogen-containing species gas for an oxidative pulse interval, and then the oxidant is removed. A method of depositing a metal oxide film using a metal halide precursor and an oxidant comprising ozone and a nitrogen-oxygen species; wherein a remote plasma is used to form the ozone and the excited nitrogen-oxygen species, wherein the excitation is performed Before the nitrogen-oxygen species are introduced into the reaction chamber, a sensor is used to monitor the excited nitrogen-oxygen species and one or more process parameters are adjusted according to the monitored excited nitrogen-oxygen species, and wherein the excited nitrogen-oxygen species , deposition rate and deposition uniformity increase. The method of claim 19, wherein the metal oxide comprises at least one of Al ₂ O ₃ , HfO ₂ , ZrO ₂ , La ₂ O ₃ and Ta ₂ O ₅ . The method of claim 19, wherein the metal halide comprises any metal in combination with any halogen element. A method for depositing a thin film on a substrate, comprising: monitoring a reactive nitrogen-oxygen species using a sensor prior to introducing the active nitrogen-oxygen species into the reaction chamber and adjusting to provide for the reaction according to the monitoring The amount of the reactive nitrogen-oxygen species in the chamber controls the deposition uniformity of the deposited film. A system for depositing a thin film on a substrate in a reaction chamber, comprising: a reaction chamber; a source of precursor reactant connected to the reactor chamber; a source of flushing gas connected to the reactor chamber; and a chamber connected to the reactor chamber An oxidant source; an activated nitrogen-containing species source coupled to the reactor chamber; the system operation and control mechanism configured to cause the system to apply an atomic layer deposition cycle to the substrate, the cycle comprising: exposing the substrate to a precursor gas for a duration Precursor pulse spacing, then removing the precursor gas; and exposing the substrate to an oxidant comprising an oxidant gas and an activating nitrogen-containing species gas for a oxidative pulse interval, then removing the oxidant; and connecting to the activated nitrogen-containing species source A sensor, wherein the sensor monitors one or more of the amount, composition, and concentration of the activated nitrogen-containing species.